Public participation in policy decisions has undoubtedly improved in recent years, yet the system is still far from perfect. Formal or “top-down” mechanisms continue to serve as a starting point, but how they interact with or are complemented by informal or “bottom-up” alternatives is to this day something of a lottery. My latest research, examining the proposed High-Speed 2 (HS2) rail link between London and the West Midlands, suggests efforts to “formalise the informal” could well constitute the next significant step.

Historically, the arena of transport infrastructure planning has been especially instructive in highlighting the enduring disconnect between those who implement policy and those whose lives stand to be affected by it. Even a cursory survey of high-profile cases from the past four decades paints an informative picture of the difficulties.

Consider, for example, the 1973 public inquiry into the projected routing of the M25 through Epping Forest. It was only as the moment of defeat neared that local campaigners finally realised the hearing’s determinedly narrow remit meant that whether the road would be built was never actually up for debate at all. In effect, the formal took the informal for a ride.

Fast-forward three years to another public inquiry, this time into plans associated with the M3’s passage through Twyford Down, Winchester. Here the interaction between the formal and the informal bordered on all-out war, the latter having decided that the only way to thwart the former was to scupper the inquiry itself through disruption and disobedience.

Compared to these episodes and many more since, the HS2 saga might seem a model of serene inclusiveness. On closer inspection, though, it raises the same old questions about how the public reacts to formal consultation opportunities and, in turn, how these reactions are incorporated – if at all – into the overall policymaking process.

The first theme to emerge from my research was the sheer frustration that the initial phase of the official consultation engendered. Members of the public criticised the quality of the information provided by HS2 Ltd and the “restrictive” nature of a questionnaire that ostensibly invited their input. As ever, it was disenchantment with the top-down approach that sparked the bottom-up response. Perceptions of a “sham” and a “foregone conclusion” led to a more organic form of public participation.

Consequently, communities up and down the proposed line set about confronting the issue on their own terms. Action groups were established. Whereas the official consultation solicited individual opinions, arguably fostering a potentially unsympathetic “Not in my back yard” attitude from the scheme’s staunchest opponents, the counter-attack gradually focused more on shared interests and the business case against HS2.

As this collective challenge gathered momentum, two discrete philosophies developed. One concentrated on high-level engagement with HS2 Ltd, drawing on the contributions of railway consultants and similar experts, while the other specialised in raising awareness of the fight through the media and other outreach strategies. “I think it’s important that we have both types of activity,” said one interviewee, “because together they give the whole thing some clout and coherence.”

Although at present we can’t gauge the precise measure of this particular movement’s success or failure, we can see how the formal/informal dynamic shifted. We can see how what began as a supposedly national exercise provoked a local response that in due course assumed its own national aspect. We can see how the reactive metamorphosed into the proactive. And we can see how both the articulate and the angry came to be dominant yet distinct voices of the cause.

Maybe the basic lesson for policymakers is that the public’s expectations have to be met from the outset. Epping Forest, Twyford Down, HS2 – perceptions of disenfranchisement are invariably the trigger for everything that follows.

The key difference nowadays, though, is that there’s much more scope for any backlash to have positive implications. The power of the internet and social networking encourages coordinated and constructive action and guards against accusations of nimbyism. Dialogue is both desired and eminently achievable. In the words of one interviewee: “I think if you’ve got a big issue – long-term national importance etc – you need a strong, clear, logical argument.”

In these circumstances, as HS2 may yet illustrate, there’s much firmer hope for meaningful interaction and less excuse for ignorance on either side’s part. There’s more to say and, by extension, a greater need to listen. It remains for the policymaking community to recognise as much and to try to make it happen.